who is rallying Los Angeles parents to fight

the unions and reform the worst public schools,

one school at a time.

When most people think of this quintessential California suburb, the Angels baseball team or Disneyland probably comes to mind. But a five-minute drive from the “happiest place on earth” takes you to Palm Lane Elementary, ground zero in a fight between teachers unions and parents who are trying to fix California’s broken public schools. The conflict—as so often in American education—boils down to unionized teachers trying to stop minority children from attending charter schools.

Ninety percent of Palm Lane students come from low-income families. About 85% are Latino, and more than half aren’t native English speakers. Palm Lane has been on the California Education Department’s list of underperforming schools since 2003. In 2013 a mere 38% of students scored proficient or better in English on state tests. And Palm Lane is hardly an exception in the area: Four other elementary schools in Anaheim rank even lower on the state’s Academic Performance Index.

But Alfonso Flores is leading a grass-roots insurgency against the union-controlled regime at Palm Lane. The former teacher and father of four kids who attend public schools in Hesperia has used the state’s “parent trigger” law, passed in 2010, to force changes at a half-dozen schools in California. The law stipulates that if a majority of parents at a struggling school sign a petition, they can compel changes in school management or personnel. Sometimes, the parents contract with a charter-school operator. In one case, they hired a new principal. Parents have also used the law as a negotiating tool to force the district to make improvements like adding more staff.

As the new school year was getting started, Mr. Flores sat down with me in the park next to Park Lane that has served as a meeting place and training ground for parents in the trigger campaign. The 45-year-old decorated Gulf War veteran has plenty of stories to tell about doing battle with teachers unions that bring heavy artillery to every fight.

Mr. Flores, a self-described “anchor baby” of Mexican immigrants, knows firsthand the value of escaping bad schools. As a child in the 1970s, he spent three hours daily on a bus trekking to and from a school in the San Fernando Valley under the Los Angeles Unified School District’s desegregation plan. Busing to achieve racial integration is hardly optimal, but Mr. Flores says it did allow him to avoid the horrendous schools in the Los Angeles inner city.

As a senior in high school, he signed up with the U.S. Army and after graduating served tours in Colombia, the Persian Gulf and Somalia. “I wanted a way to thank my country for allowing my parents to bring me to this great nation,” he explains. In 10 years the Green Beret earned a Silver Star and two Purple Hearts, and he lost a kidney after being wounded in the 1993 rescue mission in Mogadishu, Somalia, that was depicted in the movie “Black Hawk Down.”

During his military service, Mr. Flores says, he was struck by his fellow soldiers’ deficient educations. They had to “redo grammar school” because they “couldn’t write a simple report,” he recalls. “The Pentagon has complained about high-school kids not able to pass the ASVAB”—the Armed Services Vocational Aptitude Battery.

After an honorable discharge in 1998, he got his teaching credential from California State University at Dominguez Hills. His first teaching job was at Normandie Avenue, one of the worst elementary schools in L.A. One teacher, Mr. Flores recalls, would watch television while students filled in coloring sheets. A new principal tried to raise standards, he says, but if she entered a classroom without the teacher’s permission, she would get slapped with a union grievance.

In 2007, after being named a district teacher of the year, Mr. Flores was hired as the founding principal of the Global Education Academy, a charter school in South Los Angeles with an almost entirely black and Latino student population. Although most teachers were young and inexperienced, the charter far outperformed neighboring public schools. In 2008, 88% of its students scored proficient or advanced in math, compared with 37% districtwide.

The key to improving student performance, Mr. Flores says, was engaging parents. At most public schools, “parents are treated with hostility,” but at charters, administrators and teachers tend to “embrace parents as partners.” Teachers unions and their liberal allies blame poverty for bad schools, but Mr. Flores calls that an insult to good teachers who are helping poor children succeed: “Poverty is not an issue.”

In 2011 Mr. Flores joined the nonprofit Parent Revolution, inspired by the group’s role in California’s first parent-trigger campaign, at McKinley Elementary in Compton. McKinley parents wanted a high-performing charter operator to take over the failing school but were stymied by the teachers union, which had joined forces with the school district.

The union tactics at McKinley included requiring parents to show up at the school during the workday with a photo ID—a good way to scare off illegal immigrants—to verify their signatures. The trigger petition failed after a lengthy court battle, but Mr. Flores says the injustice propelled him to enlist as a parent organizer. “Before you begin a petition drive, you have to start a parent organization,” Mr. Flores says. Parents “have to be aware of how the system works and how the system is broken.”

For instance, “parents are unaware that principals don’t have power to dismiss or even hire their own staff. Districts do a really good job of keeping parents away from all of this information,” Mr. Flores notes. “Once they learn, it agitates them even more.”

But the biggest challenge is collecting signatures while being barraged by the unions. In every petition campaign, he says, “they use the same accusations and playbook.” Two standbys are false charges that the petition organizers are bribing parents to sign and that the people gathering the signatures are paid by outside groups.

The unions hit the “outsider” label hard, Mr. Flores says, alleging that petition organizers “have a political agenda—that we’re trying to privatize education.” Another union tactic: Overplay the collateral damage, telling parents that a petition could force the school to close. When all else fails, the unions try to junk the petition signatures. In the parent-trigger drive Mr. Flores helped organize at Desert Trails Elementary in Adelanto in 2012, the school board invalidated nearly 100 signatures. But a state judge ordered the district to accept the petition and allow the charter conversion.

Compared with fighting unions, Mr. Flores’s encounters with local gang leaders have been a relative breeze.

“In every campaign I’ve been a part of, you have situations where you have to respect the community,” Mr. Flores says. “That means if the local community leader is a minister, you meet with the minister. In Watts, it was a gang leader.” That was three years ago, he says, when Latino parents at Weigand Avenue Elementary were seeking to oust the principal. A black pastor said he had to get permission from a local gang to mobilize parents, and he set up a meeting at the gang leader’s apartment.

“There were all types of weapons throughout the house. I remember opening the door and that distinctive smell of marijuana,” Mr. Flores recalls. “I was afraid because I was aware of the turf battles—the fact that I was Latino and they were African-American.”

But the only triggers that came up in the meeting were of the parental variety. To Mr. Flores’s amazement, the gang members supported the Weigand Avenue takeover. One, he says, “happened to be a former student at the school and said, ‘You need to do this for the future generation of kids, because I am a product of this school.’ He was very self-aware.” While parents gathered signatures, Mr. Flores says, the gang “would egg us on and tell us they were sending parents our way.”

The petition at Weigand succeeded, but Mr. Flores says he grew frustrated by what he perceived as an inefficient use of resources at Parent Revolution. In 2014 he left to launch his own school-reform outfit, Excellent Educational Solutions.

Later that year, he got a call from Gloria Romero—the former Democratic state Senate majority leader, who co-authored the parent-trigger law—about organizing a campaign at Palm Lane in Anaheim.

Palm Lane had cycled through five principals in three years. Mr. Flores says the catalyst for the petition drive at the school was the removal of a principal who had “started making teachers accountable” by taking steps like requiring them to assign homework. Teachers howled, and soon the school board reassigned the principal—to work as a teacher at another school.

Parents went public with their outrage. Ms. Romero proposed that Mr. Flores help mobilize them for a petition drive. When presented with various trigger options, parents chose to go for a charter-school conversion.

Mr. Flores used the park outside the school for daily parent meetings. Some mornings, he says, “we had to be out here at 6:30” to catch parents before they went to work. With a three-member team and $60,000 budget, Mr. Flores gave parents a tutorial in public-school dysfunction.

“Parents don’t know about API”—the state’s Academic Performance Index—“but they know when their kids don’t have homework, it is an issue,” he says.

Once again, the union pulled out its playbook. Signature gatherers were accused of bribing parents with iPads. The Anaheim City School District superintendent wrote a letter warning parents: “It has been reported to us that there are people in our community who have been paid by an organization to gather parent signatures for a petition that could completely change the way some of our schools are run.”

The parents were unmoved. More than 60% signed the petition—but the district threw out 133 of the 488 signatures. The matter moved to the courts, and in July a state superior court judge reprimanded the district’s conduct as “unreasonable, arbitrary, capricious and unfair” and ordered the school board to accept the petition.

The school board has appealed and doubled the contract for its legal firm, to $678,000. The fight has garnered plenty of headlines in California, but state leaders like Gov. Jerry Brown and Superintendent of Public Instruction Tom Torlakson have been notably silent.

Mr. Flores notes that the Democrat-dominated legislature in Sacramento has made a point of spending big on schools with a high concentration of disadvantaged students, with little to show for it. “You could throw millions of dollars into these schools,” he says, “and if there is no accountability, you have the same situation.”

When it comes to education reform, Mr. Flores says, “parents shouldn’t be leading this, it should be the state.” But given the stakes, he adds, sounding a militant note, sometimes “you have to force change.”